Effect of clonal integration in the invasion process of Carpobrotus edulis

[Resumen] Las invasiones biológicas son una de las principales amenazas para la conservación de la biodiversidad. A pesar de los avances de los últimos años, todavía no están claros los mecanismos que subyacen en el proceso invasor de la plantas. No obstante, algunos atributos tales como la integración clonal, podrían favorecer a la expansión de algunos invasores. El objetivo de este trabajo es determinar si la integración clonal (esto es, intercambio de recursos entre individuos conectados de un sistema clonal) incrementa el crecimiento de la especie clonal invasora Carpobrotus edulis. Los resultados muestran que la capacidad de integración clonal favorece al crecimiento de C. edulis, y que por lo tanto podría contribuir a la expansión de este invasor agresivo. Este estudio apoya la idea de que los atributos clonales podrían explicar el éxito de algunas especies invasoras vegetales.[Resumo] As invasións biolóxicas son unha das principais ameazas para a conservación da biodiversidade. A pesar dos avances dos últimos anos, todavía non están claros os mecanismos que subxacen no proceso invasor das plantas. Non obstante, algún atrbutos tales como a integración clonal, poderían favorecer á expansión de algúns invasores. O obxectivo de este traballo é determinar se a integración clonal (isto é, intercambio de recursos entre individuos conectados dun sistema clonal) incrementa o crecemento da especie clonal invasora Carpobrotus edulis. Os resultados amosan que a capacidade de integración clonal favorece o crecemento de C. edulis, e que polo tanto podería contribuir á expansión deste invasor agresivo. Este estudo apoia a idea de que os atributos clonais poderían explicar o éxito dalgunhas especies invasoras vexetais.[Abstract] Biological invasions represent one of the main threats for biodiversity conservation. In spite of the effort conducted during the last years, the mechanisms underlying the processes of plant invasions remain unsolved. Some traits, as clonal integration, could promote the expansion of some plant invaders. The aim of this study is to determine if clonal integration (this is, the capacity for resource transport between connected ramets) increase the growth of the clonal invader Carpobrotus edulis. The results show that the capacity for clonal integration increases the growth of C. edulis, and therefore could contribute to the expansion of this aggressive invader. This study supports the idea that clonal traits could explain the success of some plant invasive species.Traballo fin de grao (UDC.CIE). Bioloxía. Curso 2015/201

Service learning, educational innovation and social transformation

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Learning on real robots from experience and simple user feedback

In this article we describe a novel algorithm that allows fast and continuous learning on a physical robot working in a real environment. The learning process is never stopped and new knowledge gained from robot-environment interactions can be incorporated into the controller at any time. Our algorithm lets a human observer control the reward given to the robot, hence avoiding the burden of defining a reward function. Despite the highly-non-deterministic reinforcement, through the experimental results described in this paper, we will see how the learning processes are never stopped and are able to achieve fast robot adaptation to the diversity of different situations the robot encounters while it is moving in several environments.This work was supported by the research grant TIN2009-07737 of the Spanish Ministerio de Economía y Competitividad, and María Barbeito program of the Xunta de Galicia

Hidden Granular Superconductivity Above 500K in off-the-shelf graphite materials

It has been reported that graphite hosts room temperature superconductivity. Here we provide new results that confirm these claims on different samples of highly oriented pyrolytic graphite (HOPG) and commercial flexible graphite gaskets (FGG). After subtraction of the intrinsic graphite diamagnetism, magnetization measurements show convoluted ferromagnetism and superconducting-like hysteresis loops. The ferromagnetism is deconvoluted by fitting with a sigmoidal function and subtracting it from the data. The obtained superconducting-like hysteresis loops are followed to the highest available temperature, 400K. The extrapolation of the decrease of its moment width with temperature indicates a transition temperature T$_{c}$$\sim$ 550K$\pm$50K for all samples. Electrical resistance measurements confirm the existence at these temperatures of a transition in HOPG samples, albeit without percolation. Besides, the FGG show transitions at temperatures (70K, 270K) near to those reported previously on intercalated-deintercalated graphite, confirming the general character of these superconducting transitions. These results are the first steps in the unveiling of the above room temperature superconductivity of graphite

Hakai reduces cell-substratum adhesion and increases epithelial cell invasion

BACKGROUND: The dynamic regulation of cell-cell adhesions is crucial for developmental processes, including tissue formation, differentiation and motility. Adherens junctions are important components of the junctional complex between cells and are necessary for maintaining cell homeostasis and normal tissue architecture. E-cadherin is the prototype and best-characterized protein member of adherens junctions in mammalian epithelial cells. Regarded as a tumour suppressor, E-cadherin loss is associated with poor prognosis in carcinoma. The E3 ubiquitin-ligase Hakai was the first reported posttranslational regulator of the E-cadherin complex. Hakai specifically targetted E-cadherin for internalization and degradation and thereby lowered epithelial cell-cell contact. Hakai was also implicated in controlling proliferation, and promoted cancer-related gene expression by increasing the binding of RNA-binding protein PSF to RNAs encoding oncogenic proteins. We sought to investigate the possible implication of Hakai in cell-substratum adhesions and invasion in epithelial cells. METHODS: Parental MDCK cells and MDCK cells stably overexpressing Hakai were used to analyse cell-substratum adhesion and invasion capabilities. Western blot and immunofluoresecence analyses were performed to assess the roles of Paxillin, FAK and Vinculin in cell-substratum adhesion. The role of the proteasome in controlling cell-substratum adhesion was studied using two proteasome inhibitors, lactacystin and MG132. To study the molecular mechanisms controlling Paxillin expression, MDCK cells expressing E-cadherin shRNA in a tetracycline-inducible manner was employed. RESULTS: Here, we present evidence that implicate Hakai in reducing cell-substratum adhesion and increasing epithelial cell invasion, two hallmark features of cancer progression and metastasis. Paxillin, an important protein component of the cell-matrix adhesion, was completely absent from focal adhesions and focal contacts in Hakai-overexpressing MDCK cells. The expression of Paxillin was found to be regulated by a proteasome-independent mechanism, possibly due to the decreased abundance of E-cadherin. CONCLUSIONS: Taken together, these results suggest that Hakai may be involved in two hallmark aspects of tumour progression, the lowering cell-substratum adhesion and the enhancement of cell invasion